Russian strongman Vladimir Putin doesn't deserve to be rewarded with a return trip to the White House and instead should be required to extradite to the United States the 12 intelligence officers accused of tampering in the 2016 presidential election, U.S. Sen. Bob Casey, D-Pa., said Monday.

"I don't know why [President Donald Trump] would invite him," to Washington, Casey, of Scranton, said. Putin is a "brutal dictator" and shouldn't get a "do-over" after last week's widely criticized summit in Helsinki in which Trump appeared to side with Putin on election meddling over the U.S. intelligence community,

"For him to get a forum when he's aiding and abetting the Assad regime [in Syria] when he directed operations against our election and undermined democracy all around the world," Casey said. "Why would he get another forum."

Reminded that the United States does not have an extradition treaty with Russia, making it entirely likely that the intelligence agents indicted by Special Counsel Robert Mueller will never stand trial in the United States, Casey nonetheless advocated for some alternative mechanism to bring them to justice.

Casey's remarks on Putin during an interview after a wide-ranging speech the two-term senator delivered to the monthly Pennsylvania Press Club luncheon at the Harrisburg Hilton.

In a speech, and a question-and-answer session stretching nearly an hour, Casey, who's running for re-election for a third term against Republican Lou Barletta this fall, aggressively avoided making headlines or courting controversy.

But that doesn't meant that he didn't come to the table with some strongly held views.

Casey said he had "no idea" why Trump was so deferential to Putin and it was "an outrage that he [Trump] threw our intelligence agencies under the bus."

"I don't know why he [Trump] couldn't say to him [Putin] very plainly, 'I know you did this and we don't even have to debate it. And if you do it again, there will be consequences."

That hardline stance didn't preclude engagement on other issues, such as Syria, Casey said, "but ... the idea you can pretend [election meddling] didn't happen and not confront it? The failure to do that is bad enough."

On Monday, Trump, who has continued to defend his performance in Helsinki, again took to Twitter to trash his critics.

"When you hear the Fake News talking negatively about my meeting with President Putin, and all that I gave up, remember, I gave up NOTHING," Trump wrote. "We merely talked about future benefits for both countries. Also, we got along very well, which is a good thing, except for the Corrupt Media."

When you hear the Fake News talking negatively about my meeting with President Putin, and all that I gave up, remember, I gave up NOTHING, we merely talked about future benefits for both countries. Also, we got along very well, which is a good thing, except for the Corrupt Media!

Through a campaign spokesman, Barletta said it's "shortsighted policy to ignore our adversaries rather than engage with them.

Barletta "believes we should continue to hold Russia accountable and work toward diplomatic solutions when we can," the spokesman, David Jackson, said.

Casey stood by his decision to oppose the nomination of federal Judge Brett Kavanaugh to the U.S. Supreme Court, insisting that it was still the product of a "corrupt bargain" between the White House and such hard right interests as The Heritage Foundation and The Federalist Society.

Kavanaugh's name was included on a list, formulated by those groups, of high nominees that candidate Trump, and later President Trump, said he'd exclusively rely on to fill vacancies on the high court.

"The Heritage Foundation and Federalist Society are celebrating," Casey said, adding, " ... I cannot support someone on that list.

Barletta's campaign blasted back, saying "no one is fooled by Casey's blind partisan obstruction. The people of Pennsylvania elected Bob Casey to do his job, not ignore his responsibilities to satisfy his radical base."

Casey has said he'll meet with Kavanaugh if asked, but remains a "no" vote for confirmation.

Casey never once mentioned Barletta, R-11th District, by name, or alluded to him. But he was sharply critical of the White House's tough immigration policies, which Barletta, an early Trump backer, supports.

Casey told the crowd at the Hilton that he does not support calls from some quarters on the left to abolish Immigrations and Customs Enforcement, the sub-section of the U.S. Dept. of Homeland Security that was charged with carrying out the administration's polarizing family-separation policy.

"ICE abolished? No, for sure," he said, adding that "doesn't mean like that, for any public agency, they shouldn't be subject to reviews in the appropriations process. I hope we have ICE focused on bad guys instead of current policy where they are dealing with families and kids at the border. I don't agree with the call to eliminate it."

Asked for his solution to the nation's seemingly unsolvable immigration reform issue, Casey called for an approach similar to a 2013 bill that passed with a bipartisan majority in the Senate before disappearing in the Republican-controlled U.S. House of Representatives.

Asked directly if he'd be a "yes" vote for any potential impeachment proceeding brought to the Senate, Casey said such talk was premature.

"We're still waiting on the report from [Special Counsel] Robert Mueller," Casey said "We'll just have to wait and see what's in that report."